Merck, 23813-U, SCOT Capillary GC Column

Capillary columns are basically of two type wall-coated open tubular (WCOT) and support-coated open tubular (SCOT). WCOT columns consist of a capillary tube, where the walls of the tube are coated with liquid stationary phase. In SCOT capillary columns, the inner wall of the capillary is lined with a thin layer of a particulate support, such as diatomaceous earth; onto this support material a thin layer of liquid stationary phase is then coated. This is an added advantage to the SCOT columns as it provides them larger surface area and thicker layer of stationary phase than WCOT columns.